The biggest US bank is raising its minimum wage for 18,000 tellers and other lower-level employees from $10.15 an hour to between $12 and $16.50 an hour over the next three years, depending on the market and other factors.

The bank chieftain argues that wage stagnation, income inequality and poorly trained workers are dragging down the US economy and that business has a role to pay in spreading around prosperity.

“A pay increase is the right thing to do,” Dimon wrote Tuesday in a New York Times opinion piece. “Wages for many Americans have gone nowhere for too long. Many employees who will receive this increase work as bank tellers and customer service representatives. Above all, it enables more people to begin to share in the rewards of economic growth.”

Dimon said the move will also benefit his bank, helping it attract and retain employees at the lower end of the pay scale, who also get an average of $11,000 in annual 401k, medical and other benefits.

He didn’t say how much the pay hike would cost the bank. At the same time, JPMorgan has been slimming its ranks of tellers as turns to ATMs, mobile bank and other cheaper alternatives. The bank plans to lay off about 5,000 employees by the end of next year.

On Tuesday, Dimon said the bank will invest more than $200 million this year to train thousands of its entry-level employees and help them move up the ranks rather than out the door.

“We’re on pace to train 30 percent more employees this year, many of whom are tellers,” he said. “ This type of training has helped more than 40 percent of our tellers get promoted into higher-paying roles within five years, and we now have five very senior regional directors who worked as tellers.”

Shares of JPMorgan were up 1.2 percent at $63.01 in Tuesday morning trading.